Auditory Brainstem Responses [ABR] in hyperbilirubinemic newborns

ABSTRACT

To evaluate the changes of ABR values in hyperbilirubinemic newborns, 85 cases with severe jaundice [total bilirubin levels over 16 mg/dL and direct bilirubin less than 2 mg/dL] were selected from those admitted to Children's Medical Center by simple sampling method. These infants had no other problem except jaundice. ABR was taken before treatment in all cases and in some [10 cases] after exchange transfusion or phototherapy as treatment modalities. 41 neonates [48%] had abnormal ABR values, such as increased hearing threshold, prolonged latencies of waves I, III and V [p- value<0.05], prolonged interpeak latencies of I- V and III-V [p-value<0.05], absence of waves and abnormal wave morphology. These findings could be indicative of both peripheral [8th nerve] and brainstem disturbances. After treatment ABRs showed improvement in some aspects, such as latencies of waves I, ITI and V [p value<0.05], but not in interpeak latencies [I-III, III-V and I-V] and hearing thresholds. In accordance with previous studies, there was no association between serum total bilirubin concentration and ABR test results. This could be interpreted as low significance of serum total bilirubin as a criterion for early prediction of bilirubin induced encephalopathy